[horde] Help with a snippet

[Mike Barsalou]

in horde/lib/Registry.php

there is a snippet of code in the listApps function that says this:

...

foreach ($this->applications as $app => $params)  {

...

What does this do? Can someone tell me what this line of code means?  

I am trying to track down why when using setup.php does it create a conf
line that contains the same applications twice.

For example:

what should be:

$conf['menu']['apps']=array('turba', 'kronolith'); 

is generated like:

$conf['menu']['apps']=array('turba','kronolith', 'turba','kronolith');